Short answer: TradingView’s Strategy Tester fills orders using the chart’s OHLC values, so a backtest on Heikin Ashi, Renko or Range charts uses synthetic bars and typically does not represent real market conditions. Run strategies on standard candles or use the standard OHLC option, and set commission and slippage before trusting any result.
The tester only knows the bars it is given
The Strategy Tester fills orders using the chart’s OHLC values. On a standard candlestick chart, those values are the real prices of each bar. On a chart type that transforms prices, the bars are constructed values, and the fills happen at prices that never traded.
That is why a smooth, profitable-looking equity curve on a transformed chart can say very little about what the strategy would have done with real money.
Non-standard charts are the usual trap
TradingView’s own documentation warns that backtests on Heikin Ashi, Renko, Kagi, Point and Figure and Range charts will typically not produce results representing real market conditions. Heikin Ashi charts offer an option to base order execution on standard OHLC data, which removes the biggest distortion.
If you use a transformed chart for signal clarity, check that the execution settings still reference real prices.
Set the costs yourself
A tester that assumes zero commission and zero slippage will flatter any strategy that trades often. Set the commission and slippage that match your venue, rerun the test, and compare the two curves. A strategy whose edge disappears when costs are added did not have an edge.